This invention relates to a vehicle guidance system, and particularly to a system suitable for applications in cases where a plurality of unmanned off-road dump trucks are guided at a work site such as a mine.
Unmanned vehicle guidance systems are being broadly and practically implemented which guide the movements of unmanned vehicles such as unmanned off-road dump trucks at mining sites of extensive area in the interest of releasing from hard labor, lowering production costs, and reducing fuel consumption, etc.
These unmanned vehicles carry position measurement equipment that uses GPS (global positioning system) equipment or the like to measure travel positions thereof. At a monitoring station that monitors a plurality of unmanned vehicles, meanwhile, position data for travel courses that the unmanned vehicles are to travel over are determined by means of work site surveying and/or teaching, and stored in memory. When an unmanned vehicle is sent such travel course position data via radio communications or the like, that vehicle measures its own position (and direction) with the on-board position measuring equipment, and effects vehicle steering control so that it successively reaches positions on that travel course while comparing the measured current position with the successive positions on the travel course.
One widely employed method of acquiring the travel course position data noted here is a teaching method wherewith a manned vehicle designed for teaching is actually driven and the course run is stored in memory.
In such cases, the teaching vehicle actually travels over a course, and position data are acquired for a course extending from a starting point to a target point, or for a course that extends from the starting point, passes through the target point, and returns to a finish point, so that unmanned vehicles will pass through the target points that they are supposed to reach. Another method is to acquire only the position data for the target point by teaching and then generate the courses to be run from those target point position data.
Consider, for example, the,case diagrammed in FIG. 8 where, at a mining site, there exists a dumping area 65 where an unmanned vehicle 2 is to perform the operation of transporting earth and dumping that earth, that is, an earth dumping operation. Position data for a travel course 71 that passes through a target dumping point 72 in that dumping area 65 are acquired by the teaching method.
Work sites such as mining sites of extensive area are usually unpaved, and the road surface conditions change from time to time in conjunction with the traveling of the unmanned vehicles 2. Also, during the traveling of the unmanned vehicles 2, the rock and earth loaded thereon sometimes fall onto the road surface. It sometimes happens, therefore, that potholes and/or mud is formed on the travel course obtained by teaching, making it very difficult for the vehicles to pass through. There are also cases where rocks and the like appear on travel courses obtained by teaching, making it impossible for vehicles to pass through. In this specification, the comprehensive term xe2x80x9cobstacle(s)xe2x80x9d is applied to all obstacles to vehicle travel resulting from potholes, mud, or fallen load.
In such cases, it is necessary to again conduct teaching for a new travel course that will avoid the obstacle or obstacles.
However, redoing the teaching operation every time the road surface condition changes or every time load falls from another unmanned vehicle results in the loading operations or dumping operations being interrupted and causes a sharp decline in work efficiency.
In the face of this, a method is being adopted wherewith, instead of avoiding conflict with the obstacles noted above by redoing the teaching operation, an obstacle 74 is detected by an obstacle detector 34 carried on the unmanned vehicle 2 while that vehicle is moving, as diagrammed in FIG. 9, so that each vehicle can individually alter the course it is traveling over.
In Japanese Patent Application Laid-Open No. 63-273916, Japanese Patent Application Laid-Open. No. 3-113516, and Japanese Patent Application Laid-Open No. 5-87608, for example, inventions are described wherewith obstacles ahead of a vehicle are detected by an obstacle detector carried by the vehicle, and the travel course is altered so as to avoid conflict with that detected obstacle.
Using the inventions described in the publications noted above, however, only obstacles in front of a vehicle within a range detectable by the obstacle detector can be detected. Other obstacles existing on the travel course after course alteration cannot be detected ahead of time. For that reason, when a vehicle starts to negotiate an altered travel course, there is a danger that conflicts will occur with such other obstacles.
The inventions described in the publications noted above are only able to detect obstacles of shapes that are detectable by an obstacle detector. Conversely, obstacles of a shape that is undetectable by the obstacle detector cannot be detected. Obstacle detectors are generally capable of detecting obstacles that bulge out from the road surface, that is, obstacles such as fallen load (rocks), and can alter the travel course so that such obstacles are avoided. They are not able, however, to detect potholes that constitute indentations in the road surface, or rough road surfaces, or mud or the like. For that reason, there is a danger that vehicles will run afoul of such obstacles because the travel course will not be altered to avoid them, rendering the vehicles unable to move.
A plurality of unmanned vehicles will be in operation at a work site. However, even if each of those plurality of unmanned vehicles carries an obstacle detector, there is no guarantee that every one of that plurality of vehicles will always be able to safely detect the same obstacle. More specifically, obstacle detectors generally make use of milliwave radar, laser radar, or visual sensors, wherewith the obstacle detection precision is affected by the S/N ratio.
Work sites such as mining sites tend to become dusty. Thus it happens that such dust constitutes noise when obstacles are being detected by obstacle detectors, making it very difficult to distinguish between those obstacles and the surrounding environment. It is thus possible that, depending on changes in the surrounding environment, even if an obstacle can be detected by the obstacle detector carried on one unmanned vehicle, that same obstacle might not be detectable with the obstacle detector carried on another unmanned vehicle. There is therefore a danger that the unmanned vehicle that could not detect the obstacle will run afoul of that obstacle.
In Japanese Patent Application Laid-Open No. 10-38586, an invention is described wherewith, instead of detecting obstacles ahead of vehicles by obstacle detectors, the obstacles are registered beforehand, and an alarm is issued when a vehicle approaches such a pre-registered obstacle to alert the operator to be careful.
In the invention described in this publication, the positions of obstacles to a snow removal vehicle are stored beforehand in a memory medium carried on board the snow removal vehicle. Provision is made so that, while the snow removal vehicle is in operation, the data in that memory medium are sequentially read out, and an alarm is issued when an obstacle stored in that memory medium is approached to alert the operator to be careful.
According to the invention described in the publication noted above, only those obstacles that have been pre-stored in the memory medium can be detected and avoided. Conversely, newly developed obstacles that have not been pre-stored in the memory medium cannot be detected or avoided.
To be sure, the problem of overlooking obstacles will not occur in applications in cases where fixed obstacles are detected, and no new ones develop, as in snow removal vehicle operations, with respect to ditches and road shoulders and the like that are covered with snow.
When the invention described in the publication noted above is employed at work sites such as mining sites of extensive area where pluralities of unmanned vehicles are operated, however, problems arise in that newly developed obstacles are overlooked and already removed obstacles are erroneously detected as obstacles.
More specifically, at mining sites of extensive area, objects (load) fall from the unmanned dump trucks from time to time. And, even when such obstacles (load) do fall, they may be promptly discovered and removed by a manned vehicle such as a bulldozer. There will also be cases where another manned work vehicle such as a bulldozer or fuel truck or the like will be stopped on the travel course of an unmanned dump truck. In such cases, the manned work vehicle constitutes an obstacle to the unmanned vehicle. Also, the positions where such manned vehicles that constitute obstacles stop change from time to time. Thus the obstacles are not stationary or fixed at work sites such as this where a plurality of vehicles is being operated. New obstacles will develop, or be removed, and the positions thereof will change from time to time, as the vehicles travel about.
Accordingly, when the invention described in the publication noted above is employed, there will be cases where newly developed obstacles other than those obstacles pre-stored in the memory medium are overlooked, thus giving rise to the possibility that a vehicle will run afoul of such obstacles. Problems will also arise when, conversely, obstacles already removed are erroneously recognized as existing obstacles and unnecessary course changes are made or the vehicle is stopped unnecessarily.
In other words, the invention described in Japanese Patent Application Laid-Open No. 10-38586 is not able to cope with work sites where the obstacles change in real time, such as work sites where pluralities of vehicles are operated.
The objects of the present invention, which was devised in view of the situation described in the foregoing, are as follows.
(1) To provide for altering the travel course when an obstacle develops, with good work efficiency (altering the travel course with better work efficiency than with methods based on teaching).
(2) To eliminate the overlooking of obstacles and the erroneous recognition of obstacles even at work sites where the obstacles change in real time, such as at work sites where pluralities of vehicles are being operated.
(3) To make it possible to capture obstacles without fail, even when they are obstacles existing within a range undetectable by the obstacle detector, or are obstacles of an undetectable shape.
(4) To make it possible to capture objects without fail, irrespective of noise surrounding the obstacle or other surrounding environment.
Other objects are described next.
The teaching procedure described earlier exhibits great capability in operations where the same course is traveled repeatedly. At sites where the shape of the course changes frequently, however, the operation of producing course data by teaching must be done frequently, wherefore the capability thereof is severely limited.
In a loading area at a mining site, for example, the positions of loading equipment such as wheel loaders or power shovels are subject to change at any time as the work progresses. In a dumping area at a mining site, on the other hand, dumping is not only done at a fixed dumping facility (pit), but the procedure of dumping while successively altering the dumping position within a dumping area having a certain breadth is also employed.
With the teaching procedure described earlier, it is necessary to teach a new course every time the position of the loading equipment or the dumping position changes, and that necessity severely impairs the personnel reduction benefit of an unmanned dumping system.
In order to cope with changing work sites like this, the method of altering once prepared courses and then using them, and the method of guiding the vehicles by radio control have been proposed.
Specifically, in Japanese Patent Application Laid-Open No. 5-257529, a method is proposed wherewith, after guiding a vehicle by radio control, a course for returning to the circuit course (original course) is generated.
It is possible to guide a vehicle to any location using such radio control, in like manner as in manual operations, but personnel are then needed to operate the radio control. When a vehicle is guided from outside using a joy stick or the like, moreover, a very difficult and onerous operation is required that involves continually switching between the direction of advance of the vehicle and the operator""s own point of view, as has been demonstrated by actually employing radio control equipment.
To avoid the difficulties of such radio control operations, there are cases also where most of the work is done by unmanned operations, but when loading operations are done, operators climb into vehicles and perform the operation.
A method has also been proposed, in Japanese Patent Application Laid-Open No. 9-44243, wherewith courses are produced from a branching point in a scheduled course (original course) using cubic curves.
This method exhibits higher utility in actual use than does the method using radio control, but it suffers shortcomings in that the range wherein the vehicle can be guided is limited by the cubic curve, and in that there is a possibility of conflict with a vehicle when an obstacle exists within the guidance range.
The occurrence of conflicts cannot be verified unless a vehicle is actually test-operated, wherefore adequate monitoring is necessary during operation, and it is also very difficult to use unless the work site allows a sufficiently flat guidance range to be prepared beforehand.
There is a proposal made in Japanese Patent Application Laid-Open No. 8-101712 that takes conflicts with obstacles into consideration after planning vehicle travel routes. This involves teaching for straight line segments and other simple segments but teaching with an actual vehicle for complex segments where there is a great possibility of conflict.
With this method, teaching for the loading segments has to be repeated as a loading operation progresses, so there is no hope of improving utilization convenience.
Furthermore, a method has been proposed (in Japanese Patent Application Laid-Open No. 1-173300) wherewith the shape of an extremely confined course area such as a parking area is detected with a revolving ultrasound sensor, and the ideal steering angle for entering that parking area is found from a database and indicated to the driver.
With that method, however, it is impossible to operate unmanned traveling vehicles that move freely while changing the steering angle within course areas that are both large and complex while avoiding conflicts.
In other words, unlike a parking area, the shapes of and target positions in course areas at loading sites in mining facilities differ over a very broad range. Also, it is very difficult in practice to create a database for finding one-to-one course data from the shape of that course area, etc., and hence a more general-purpose method is deemed necessary.
Furthermore, in route searches for general articulated industrial robots, the concept of a configuration coordinate system wherein the angle at each axis is taken in a coordinate axis is widely used. In view of the fact that each robot axis can move independently, it is possible for a robot to move in a straight line passing through any two points within that space. (Conversely, it is not always possible for a robot to move between any two points given in three-dimensional space.) By using this space, the maze method and various other route search techniques have been devised.
In the space described above, if a route is first produced which will avoid conflict with obstacles, that route will always be negotiable. That is, it will be possible to effect route searches that consider obstacle avoidance only, giving no thought to the problem of route negotiability.
This configuration coordinate system concept cannot be used in unmanned vehicles which operate with steering controls. That is, even if the positions of two points in a plane, and directions of vehicle advance at those position, are prescribed, an unmanned vehicle that only has functions for moving forward and in reverse, and steering, cannot move over a route that connects the positions noted above with straight lines.
That is, even if a route is planned which gives the priority to obstacle avoidance, it will be impossible for an ordinary vehicle that operates with steering controls and the like, specifically a vehicle having steering mechanisms such as a front wheel steering mechanism, rear wheel steering mechanism, four wheel steering mechanism, and articulation, to negotiate that course.
In FIG. 37, for example, a route between two points is represented which takes an obstacle into consideration. In this case, however, it is clearly impossible for vehicle A to move.
Given the conditions diagrammed in FIG. 37, a route such as that diagrammed in FIG. 38 is desirable.
In order to resolve the problem described in the foregoing, there are cases where the vehicle mechanisms are modified and a vehicle is designed which is capable of moving in all directions. Extra steering mechanisms not only involve increased costs, however, but high-speed driving stability is lost, wherefore such are not suitable for applications to unmanned vehicles used at mining sites where high-speed travel is demanded.
In view of the situation described in the foregoing, an object of the present invention is to provide an unmanned vehicle guidance system wherewith guidance courses can easily be prepared that are responsive to changes in course area shape and changes in movement target positions, and wherewith vehicles can be prevented from conflicting with course area boundaries and excavation faces.
Thereupon, a first invention is a vehicle guidance system for guiding a plurality of vehicles, comprising:
memory means for storing positions of obstacles at a work site common to the plurality of vehicles when that plurality of vehicle travel simultaneously over that work site;
updating means for updating content stored in the memory means; and
guidance means for guiding the.plurality of vehicles based on the content stored in the memory means so that those vehicles do not conflict with the obstacles.
Based on the first invention, as diagrammed in FIG. 3 and FIG. 12(a), when an obstacle 74 has been detected, etc., the position of that obstacle 74 is stored in the memory means 41, considering that position as an obstacle 74 common to a plurality of vehicles 2, 2 . . . . Then, as the multiple vehicles 2, 2 . . . travel, the content stored in the memory means 41 is continually updated.
Guidance is effected, based on the content stored in the memory means 41, so that there is no conflict with the obstacle 74. That is, conflicting objects are avoided by stopping before they are reached, etc.
According to this invention, as described in the foregoing, provision is made so that the position of the obstacle 74 common to the plurality of vehicles 2, 2 . . . is stored in the memory means 41, and so that the content stored in the memory means 41 is updated in conjunction with the traveling of the plurality of vehicles 2, 2 . . . . Therefore, even should one vehicle overlook or erroneously recognize something as an obstacle, that which has been accurately judged by another vehicle will be recorded as an obstacle. Accordingly, even if at a work site where the obstacles change in real time, as at a work site where multiple vehicles are traveling about, there will cease to be obstacles that are overlooked and erroneous judgments of things as obstacles.
A second invention is a vehicle guidance system in which each of a plurality of vehicles is provided with vehicle position measurement means for measuring a current position of its own vehicle, when position data for target points that should be reached by each of the plurality of vehicles are given, data are generated for travel courses that pass through those target points and each of the plurality of vehicles is guided along its proper travel course while comparing the current vehicle position measured by the vehicle position measurement means with positions on the generated travel course,
the vehicle guidance system comprising:
memory means for storing positions of obstacles at a work site common to the plurality of vehicles when the plurality of vehicles travel simultaneously over that work site;
updating means for updating content stored in the memory means;
travel course generation means which, when position data on the target points are given, generates data for travel courses that pass through those target points, based on the content stored in the memory means, such that there is no conflict with the obstacles; and
guidance means for guiding the plurality of vehicles, respectively, along the travel courses generated by the travel course generation means.
Based on the second invention, as diagrammed in FIG. 3 and FIG. 12(a), when an obstacle 74 has been detected, etc., the position of that obstacle 74 is stored in the memory means 41, considering that position as an obstacle 74 common to a plurality of vehicles 2, 2 . . . . Then, as the multiple vehicles 2, 2 . . . travel, the content stored in the memory means 41 is continually updated.
Then, when position data for the target points 72, 72 . . . for each of the plurality of vehicles 2, 2 . . . are given, data are generated for travel courses 71xe2x80x2, 71xe2x80x2 . . . that pass through those target points 72, 72 . . . , based on the content recorded in the memory means 41, so that there is no conflict with the obstacle 74. Then the plurality of vehicles 2, 2 . . . , respectively, is guided along the travel courses 71xe2x80x2, 71xe2x80x2 . . . .
According to this invention, as described in the foregoing, provision is made so that the position of the obstacle 74 common to the plurality of vehicles 2, 2 . . . is stored in the memory means 41, and so that the content stored in the memory means 41 is updated in conjunction with the traveling of the plurality of vehicles 2, 2 . . . . Therefore, even should there be an obstacle that one vehicle overlooked, that which has been accurately judged by another vehicle will be recorded as an obstacle. Accordingly, even if at a work site where the obstacles change in real time, as at a work site where a plurality of vehicles is traveling about, obstacles will no longer be overlooked.
Based on this invention, moreover, the position, of the obstacle 74 common to the plurality of vehicles 2, 2 . . . is stored in the memory means 41, wherefore it becomes possible to perform the operation of revising the travel courses 71, 71 . . . for the plurality of vehicles 2, 2 . . . easily and in a short time from the content recorded in the memory means 41. For that reason, the operation of revising the travel courses 71, 71 . . . can be done with good work efficiency. Work efficiency will be dramatically improved compared to the teaching operation wherewith a special teaching vehicle must be operated every time an obstacle develops.
A third invention is a vehicle guidance system in which each of a plurality of vehicles is provided with vehicle position measurement means for measuring a current position of its own vehicle, when position data for target points that should be reached by each of the plurality of vehicles and position data for a course area capable of being traveled by the plurality of vehicles are given, data are generated for travel courses that travel inside that course area and pass through those target points and each of the plurality of vehicles is guided along its proper travel course while comparing the current vehicle position measured by the vehicle position measurement means with positions on the generated travel course;
the vehicle guidance system comprising:
memory means for storing positions of obstacles at a work site common to the plurality of vehicles when that plurality of vehicle travel simultaneously over that work site;
updating means for updating content stored in the memory means;
travel course generation means which, when position data on the target points and position data on the course area are given, generates data for the travel courses that travel inside the course area and pass through the target points, based on the content stored in the memory means, such that there is no conflict with the obstacles; and
guidance means for guiding the plurality of vehicles, respectively, along the travel courses generated by the travel course generation means.
Based on the third invention, as diagrammed in FIG. 3 and FIG. 12(a), when an obstacle 74 has been detected, etc., the position of that obstacle 74 is stored in memory means 41, considering that position as an obstacle 74 common to a plurality of vehicles 2, 2 . . . . Then, as the multiple vehicles 2, 2 . . . travel, the content stored in the memory means 41 is continually updated.
Then, when position data for the target points 72, 72 . . . for each of the plurality of vehicles 2, 2 . . . and position data for the course area 65 are given, data are generated for travel courses 71xe2x80x2, 71xe2x80x2 . . . that travel inside the course area 65 and pass through those target points 72, 72 . . . , based on the content recorded in the memory means 41, so that there is no conflict with the obstacle 74. Then the plurality of vehicles 2, 2 . . . , respectively, is guided along the travel courses 71xe2x80x2, 71xe2x80x2 . . . .
Based on this third invention, the same effectiveness as with the second invention is realized. Based on the third invention, however, the vehicle 2 is guided so that it does not conflict with the untravelable area outside the course area 65.
A fourth invention is the third invention, comprising: display means for displaying the course area on a display screen; and
obstacle indication means for indicating positions of obstacles on the display screen based on relative positional relationship thereof with the course area on the display screen;
wherein the memory means stores the positions of obstacles on the display screen indicated by the obstacle indication means as positions of obstacles common to the plurality of vehicles; and
the updating means updates the content stored in the memory means every time the position of an obstacle is newly indicated by the obstacle display means.
Based on the fourth invention, the same benefits as with the third invention are realized.
Furthermore, based on the fourth invention, as diagrammed in FIG. 12(a), when an operator has discovered an obstacle 74, the position where the obstacle 74 appeared or disappeared can be indicated accurately on the screen in a relative positional relationship with the course area (dumping area) 65 on the display screen 76.
Based on this fourth invention, provision is made so that the operator visually verifies the obstacle 74 to be an obstacle, wherefore even an obstacle 74 that exists in a range that cannot be detected by the obstacle detector 34 carried on an unmanned vehicle or an obstacle 74 of a shape that cannot be detected (pothole, mud, rough road surface, etc.) can be judged to be an obstacle.
Based on this fourth invention, furthernore, because provision is made so that an operator visually verifies the obstacle 74 to be an obstacle, obstacles 74 can be ascertained more definitely, irrespective of the surrounding environment, as compared to when they are detected by an obstacle detector 34.
A fifth invention is the third invention, comprising: display means for displaying on a display screen the course area and, of the travel courses generated by the travel course generation means, a traveled travel course or courses that have already been traveled over by the vehicles; and
obstacle indication means for indicating positions of obstacles on the display screen based both on relative positional relationship thereof with the course area on the display screen and on relative positional relationship with the traveled travel course or courses on the display screen;
wherein the memory means stores the positions of obstacles on the display screen indicated by the obstacle indication means as positions of obstacles common to the plurality of vehicles; and
the updating means updates the content stored in the memory means every time the position of an obstacle is newly indicated by the obstacle display means.
Based on the fifth invention, the same benefits as with the third invention are realized.
Based on the fifth invention, furthermore, as diagrammed in FIG. 12(a), when an operator has discovered an obstacle 74, the position where the obstacle 74 appeared can be indicated on the screen in a relative positional relationship with the course area (dumping area) 65 on/the display screen 76.
At work sites at mining sites of extensive area, obstacles 74 such as rocks mainly come into being when load falls from a vehicle 2. Accordingly, such obstacles 74 will often be positioned on a traveled travel course 71xe2x80x3 that a vehicle 2 has completed a run over.
Here, as diagrammed in FIG. 12(b), a traveled travel course 71xe2x80x3 is being displayed on the display screen 76, wherefore the generation position of an obstacle 74 such as a rock or the like can be determined even more accurately in a relative positional relationship with this traveled travel course 71xe2x80x3. That is, an operator can revise the position of an obstacle 74 judged in the relative positional relationship with the course area 65 (dumping area), judging it to be positioned at 74xe2x80x2 on the traveled travel course 71xe2x80x3, and thus accurately indicate the position of the obstacle 74.
Based on this fifth invention, because provision is made so that an operator visually verifies the obstacle 74 to be an obstacle, obstacles 74 can be ascertained more definitely, irrespective of the surrounding environment, as compared to when they are detected by an obstacle detector 34.
A sixth invention is the third invention, comprising: display means for displaying the course area on a display screen;
obstacle indication means for indicating positions of obstacles on the display screen based on relative positional relationship thereof with the course area on the display screen; and
revision means for revising the positions of obstacles indicated by the obstacle indication means, based on data on the traveled travel course or courses over which the vehicles have already traveled, of the travel courses generated by the travel course generation means;
wherein the memory means stores the obstacle positions revised by the revision means as positions of obstacles common to the plurality of vehicles; and
the updating means updates the content stored in the memory means every time an obstacle position newly indicated by the obstacle indication means is revised by the revision means.
Based on the sixth invention, the same benefits as with the third invention are realized.
Based on the sixth invention, furthermore, as diagrammed in FIG. 12(a), when an operator has discovered an obstacle 74, the position where the obstacle 74 appeared can be indicated on the screen in a relative positional relationship with the course area (dumping area) 65 on the display screen 76.
At work sites at mining sites of extensive area, obstacles 74 such as rocks mainly come into being when load falls from a vehicle 2. Accordingly, such obstacles 74 will often be positioned on a traveled travel course 71xe2x80x3 that a vehicle 2 has completed a run over.
Here, as diagrammed in FIG. 12(b), the position where an obstacle 74 appeared, such as a rock or the like, indicated by an operator, is automatically revised to the accurate position 74xe2x80x2, based on position data for the traveled travel course 71xe2x80x3.
Based on this sixth invention, because provision is made so that an operator visually verifies the obstacle 74 to be an obstacle, obstacles 74 can be ascertained more definitely, irrespective of the surrounding environment, as compared to when they are detected by an obstacle detector 34.
A seventh invention is the first invention or the second invention or the third invention, in which some or all of the plurality of vehicles comprise obstacle detection means for detecting obstacles; the vehicle guidance system further comprising:
obstacle position measurement means for measuring positions of those obstacles based on position of a vehicle when an obstacle has been detected by the obstacle detection means; and
wherein the memory means stores the positions of obstacles measured by the obstacle position measurement means as positions of obstacles common to the plurality of vehicles; and
the updating means updates the content stored in the memory means, based on the position of a new obstacle measured by the obstacle position measurement means, every time a new obstacle is detected by the obstacle detection means.
Based on the seventh invention, the same benefits are realized as with the first invention or the second invention or the third invention.
Based on the seventh invention, the following benefit is also realized.
That is, based on the seventh invention, as diagrammed in FIG. 9, an obstacle 74 detected by one vehicle 2 will be stored in the memory means 41 as an obstacle 74 to other unmanned vehicles 2. Hence another vehicle 2 will be able to avoid the obstacle 74 without fail, even if that obstacle 74 could not be detected by the obstacle detection means 34 carried on board that other vehicle 2. In other words, even in cases where the obstacle detection means 34 of another vehicle 2 fail or operate uncertainly, or where the obstacle 74 cannot be detected precisely due to the influence of the surrounding environment, that other vehicle 2 can nevertheless safely avoid the obstacle 74.
An eighth invention is the first invention or the second invention or the third invention, in which some or all of the plurality of vehicles comprise:
road surface condition detection means for detecting a road surface condition; and
determination means for determining that a current road surface is an obstacle based on the road surface condition detected by the road surface condition detection means;
wherein the memory means stores position of a vehicle at the time when the current road surface was determined to be an obstacle by the determination means as position of an obstacle common to the plurality of vehicles; and
the updating means updates the content stored in the memory means every time the determination means determines a new obstacle.
Based on the eighth invention, the same benefits are realized as with the first invention or the second invention or the third invention.
Based on the eighth invention, the following benefit is also realized.
That is, based on this eighth invention, a vehicle 2 determines from the condition of the road surface over which it travels that that is an obstacle 74, wherefore even an obstacle 74 that cannot be detected by the obstacle detection means 34 (cf. FIG. 9) carried on the vehicle (such as mud, a pothole, or rough road surface, etc.) can be determined to be an obstacle.
A ninth invention is the first invention or the second invention or the third invention, in which some or all of the plurality of vehicles comprise:
reception means for receiving signals from other manned vehicles indicating that an obstacle exists in vicinity of its own vehicle;
transmission means for transmitting signals indicating position of its own vehicle when a signal is received indicating that an obstacle exists in vicinity of its own vehicle; and
obstacle position measurement means for receiving signals indicating a vehicle position transmitted from the transmission means and for measuring positions of obstacles near that vehicle based on the vehicle position received;
wherein the memory means stores the positions of obstacles measured by the obstacle position measurement means as positions of obstacles common to the plurality of vehicles; and
the updating means updates the content stored in the memory means, based on the position of a new obstacle measured by the obstacle position measurement means, every time a signal is received by the reception means indicating that a new obstacle exists.
Thus, based on the ninth invention, the position of an obstacle 74 is measured on the basis of the position of a vehicle 2 that has been sent a signal indicating the presence of an obstacle near that selfsame vehicle, that is, more specifically, that has been sent a stop command, and those data are stored in the obstacle memory unit 41.
Based on the ninth invention, the same benefits are realized as with the first invention or the second invention or the third invention.
A tenth invention is the first invention or the second invention or the third invention, wherein, when a manned or unmanned work vehicle having vehicle position measurement means for measuring position of its own vehicle is present inside an area traveled over by the plurality of vehicles, the memory means stores the position of the work vehicle measured by the vehicle position measurement means as position of an obstacle common to the plurality of vehicles, and the updating means updates the content stored in the memory means every time the position of the work vehicle is altered by the vehicle position measurement means.
In other words, there are times when a work vehicle such as a manned vehicle 20 or loading machine 14 or the like becomes an obstacle to the traveling of a plurality of unmanned vehicles 2, 2 . . . , as diagrammed in FIG. 7.
Thereupon, as diagrammed in FIG. 3, the measured positions transmitted from the work vehicles 20 and 14 are stored as the positions of obstacles 74 in the memory means 41. Then, every time the measured positions of the work vehicles 20 and 14 change, as they may at any time, the content stored in the memory means 41 is updated.
Then, based on the content stored in the memory means 41, the vehicles 2 are guided so that they avoid the obstacles 74.
Based on the tenth invention, the same benefits are realized as with the first invention or the second invention or the third invention.
An 11th invention is the tenth invention, wherein the updating means updates the content stored in the memory means every time the positions of the work vehicles are successively changed in conjunction with traveling of the work vehicles.
Based on the 11th invention, the updating of the stored positions of the obstacles 74 is done at any time, so long as the vehicle positions are being changed, irrespective of whether the work vehicles 20 and 14 are travelling or stopped.
A 12th invention is the tenth invention, wherein the updating means updates the content stored in the memory means every time the work vehicle stops traveling and stopped position of that work vehicle is changed.
Based on the 12th invention, the updating of the stored positions of the obstacles 74 is not done while the work vehicles 20 and 14 are traveling, but only when those work vehicles 20 and 14 are stopped.
A 13th invention is a vehicle guidance system comprising: vehicle position measurement means for measuring a current position of its own vehicle, and being constructed such that, when position data for target points that should be reached by the vehicle and position data for a course area where the vehicle can travel are given, data for a travel course that enables the vehicle to travel inside the course area and to pass through the target points are generated; and the own vehicle is guided over that travel course while comparing current vehicle positions measured by the vehicle position measurement means and position on the generated travel course;
the vehicle guidance system comprising:
indication means for indicating positions of target points inside the course area;
indication means for indicating the position of a movement starting point inside the course area, the direction of a vehicle at the movement starting point, the position of a target point inside the course area, and the direction of a vehicle at the target point;
travel course generation means for generating travel course data wherewith the vehicle departs the movement target point in the indicated vehicle direction, alters the direction of advance thereof, reversing direction at one or more direction reversal points, and, arrives at the target point in the indicated vehicle direction, so that, when position data indicating the boundary line of the course area are given, and the position of the movement starting point, the vehicle direction at the movement starting point, the position of the target point, and the vehicle direction at the target point are indicated by the indication means, the vehicle can travel over the interior enclosed by the boundary line of the course area and also turn around with a turning radius equal to or greater than the minimum turning radius of the vehicle; and
guidance means for guiding the vehicle over the travel course generated by the travel course generation means.
Based on the 13th invention, travel courses can easily be generated that cope with changes in the shape of the course area and changes in the positions and directions of the target points, without performing travel course teaching using an actual vehicle.
Also, because travel courses are generated so that the vehicles travel inside the course area, vehicles are prevented before the fact from conflicting with course area boundaries or excavation faces.
A 14th invention is an unmanned vehicle guidance system for guiding unmanned vehicles over guidance courses based on travel positions of those unmanned vehicles measured by travel position measurement means and course data defining guidance courses for the unmanned vehicles; the unmanned vehicle guidance system comprising:
means for inputting a shape of a course area;
means for respectively indicating the position of a movement starting point and the direction of advance of the unmanned vehicle at that position, and the position of a movement target point and the direction of advance of the unmanned vehicle at that position;
means for producing course data wherewith the indicated position and the direction of advance are satisfied at the movement starting point and at the movement target point, and wherewith the direction of advance of the unmanned vehicle changes at one or more direction reversal points provided between the movement starting point and the movement target point;
means for producing course data wherewith the indicated position and direction of vehicle advance are satisfied at the position of the movement starting point and at the movement target point;
means for inferring conflicts between the course area and the unmanned vehicle when the unmanned vehicle is made to travel over a guidance course defined by the produced course data, based on data relating to the unmanned vehicle; and
course data alteration means for altering the course data when a conflict has been inferred.
Based on the 14th invention, guidance courses can easily be generated that cope with changes in the shape of the course area and changes in movement target positions, without performing guidance course teaching using an actual vehicle.
Moreover, in addition to inferring conflicts between unmanned vehicles traveling over the generated guidance courses and the boundaries of the course area, the course data are altered when such a conflict has been inferred, Accordingly, conflicts between unmanned vehicles and course area boundaries or excavation faces can be prevented before the fact.
A 15th invention is the 14th invention wherein the means for producing course data comprises:
means for generating position of an intermediate point in the guidance course inside the course area and direction of vehicle advance at that position; and
means for connecting position of the movement starting point, position of the intermediate point, and position of the movement target point, with a circular arc or arcs and/or straight line or lines, so as to pass through each of those positions, and such that the direction of vehicle advance at each of those positions coincides either with direction of a tangent to such circular arc or arcs or with direction of such straight line or lines;
wherein the course data alteration means alters the course data by altering the position of the intermediate point when the conflict has been inferred.
Based on this 15th invention, the guidance course is produced using an intermediate point, wherefore it is possible easily to generate a route that reverses direction at the intermediate point. As a consequence, routes can be freely planned that contain direction reversals.
Moreover, guidance courses are produced by connecting the position of the movement starting point, the position of the intermediate point, and the position of the movement target point, by circular arcs, tangents, or both, wherefore the guidance course can be produced efficiently.
A 16th invention is the 14th invention wherein the means for producing course data comprises:
means for generating position of an intermediate point in the guidance course inside the course area and direction of vehicle advance at that position; and
means for connecting position of the movement starting point, position of the intermediate point, and position of the movement target point, with a spline curve, so as to pass through each of those positions, and such that direction of vehicle advance at each of those positions coincides with direction of a tangent to the spline curve;
wherein the course data alteration means alters the course data by altering the position of the intermediate point when such conflict has been inferred.
Based on the 16th invention, the same benefits are realized as with the 15th invention.
A 17th invention is the 14th invention wherein the means for producing the course data comprises:
means for generating position of an intermediate point in the guidance course inside the course area and direction of vehicle advance at that position; and
means for connecting position of the movement starting point, position of the intermediate point, and position of the movement target point, with a spline curve and a circular arc, or with a spline curve and a straight line or lines, so as to pass through each of those positions, and such that direction of the vehicle advance at each of those positions coincides with direction of a tangent to that spline curve, direction of a tangent to such circular arc, or direction of such straight line or lines;
wherein the course data alteration means alters the course data by altering the position of the intermediate point when such conflict has been inferred.
By this 17th invention also, the same acting benefits are realized as with the 15th invention.
An 18th invention is either the 15th or the 17th invention, wherein the means for producing the course data comprises:
evaluation means for evaluating the course data using distances between the guidance course and boundaries of the course area; and
selection means for selecting course data having best evaluation values out of a plurality of generated course data.
Based on this 18th invention, course data are evaluated, and those course data having the best evaluation values are selected, wherefore it is possible to evaluate and select course data wherewith conflict will not occur between the unmanned vehicles and the boundaries of the course area.
A 19th invention is either the 15th or the 17th invention, wherein the means for producing the course data comprises:
evaluation means for evaluating the course data using a function between distances between the guidance course and boundaries of the course area, and minimum radius of the guidance course; and
selection means for selecting course data having best evaluation values out of a plurality of generated course data.
Based on this 19th invention, it is possible to evaluate and select course data wherewith conflict will not arise between the unmanned vehicles and the boundaries of the course area, and wherewith the turning of the unmanned vehicles will not be hindered.
A 20th invention is an unmanned vehicle guidance system for guiding unmanned vehicles over guidance courses based on travel positions of those unmanned vehicles measured by travel position measurement means and course data defining guidance courses for the unmanned vehicles; the unmanned vehicle guidance system comprising:
means for inputting shape of a course area;
means for producing course data;
means for inferring conflicts between the course area and the unmanned vehicle when the unmanned vehicle is made to travel over a guidance course defined by the produced course data, based on data relating to the unmanned vehicle;
course data alteration means for altering the course data when the conflict has been inferred; and
mode setting means for setting an automatic operation mode when the unmanned vehicle is being guided using the generated course data, and for setting a measurement mode when shape of the course area is being input.
Based on this 20th invention, an automatic operation mode or a measurement mode can be selectively set, wherefore such problems as an unmanned vehicle operating automatically while in the measurement mode, or a course area shape being input when in automatic operation can be avoided. An operator can selectively set either of those modes, moreover, so work efficiency is enhanced.
A 21st invention is an unmanned vehicle guidance system for guiding unmanned vehicles over guidance courses based on travel positions of those unmanned vehicles measured by travel position measuring means and course data defining guidance courses for the unmanned vehicles, the unmanned vehicle guidance system comprising:
means for inputting shape of a course area;
means for producing course data;
mode setting means for causing can unmanned vehicle be guided using the generated course data when the automatic operation mode has been set, and for collecting course area shape data by causing the unmanned vehicle be guided along a course area and detecting positions traveled by the unmanned vehicle when a measurement mode has been set.
means for recognizing a shape change zone of the course area; and
course area shape updating means for updating shape of the course area so that the course area shape is altered only in the zone whose shape has been changed.
Based on this 21st invention, a shape change zone is recognized, and the shape a of the course area is updated only in that shape change zone, wherefore the frequency of course area shape input operations can be reduced to the extent possible.
A 22nd invention is the 21st invention wherein the means for recognizing the shape change zone of the course area comprises:
a moving body for measuring that moves through the course area;
movement position measurement means for measuring movement position of the moving body for measuring; and
means for specifying the shape change zone based on the movement position of the moving body for measuring and an area occupied by that moving body.
Based on this 22nd invention, the shape change zone is specified on the bases of the movement position of the moving body for measuring and the area occupied by the moving body. Accordingly, if the course area is a mining operation area, for example, a work machine for performing such operations as loading in the course area can be used as the moving body for measuring.
A 23rd invention is the 21st invention wherein the means for recognizing the shape change zone of the course area comprises:
position measurement means for measuring three-dimensional positions of digging unit of a work machine for digging operations in the course area;
ground height measurement means for measuring initial ground height in the course area; and
means for specifying the shape change zone of the course area based on position of the digging unit and area occupied thereby when height of the digging unit and the initial ground height coincide.
Based on this 23rd invention, changes in the course area are detected from the fact that the height of the digging unit of a work machine for performing digging. operations has coincided with the ground height in the course area, and the shape change zone is specified based on the digging unit position and area occupied. As a consequence, the shape change zone can be specified without provided special measurement means.
A 24th invention is any one of the 14th, 20th, or 21st invention, wherein the travel position measurement means is a GPS, and means for inputting shape of the course area comprises:
means for switching a position measured by the GPS to a position measured at left edge or right edge of the unmanned vehicle; and
indication means for indicating whether to switch to position measured at the left edge or to position measured at the right edge.
Based on this 24th invention, a position measured by the GPS is switched to a position measured either at the left edge or right edge of the unmanned vehicle, wherefore, by causing the unmanned vehicle to travel while bringing either the left edge or the right edge of the unmanned vehicle up to the boundary of the course area, the shape of the course area can be precisely input by a so-called teaching procedure.
A 25th invention is any one of the 14th, 20th, or 21st inventions, wherein the travel position measurement means is a GPS, and means for inputting shape of the course area comprises means for selectively altering position of antenna of the GPS to left edge or right edge of the unmanned moving body.
Based on the 25th invention, the position of the GPS antenna can be selectively altered between the left edge and right edge of the unmanned moving body, wherefore, by causing the unmanned vehicle to travel while bringing either the left edge or the right edge of the unmanned vehicle up to the boundary of the course area, the shape of the course area can be precisely input by a so-called teaching procedure.
A 26th invention is the 13th invention wherein the vehicle is an unmanned vehicle that is loaded with a load by a loading machine, and the course area position data are updated by excluding a certain area referenced to current position of the loading machine from current course area.
Based on this 26th invention, as diagrammed in FIG. 40(a), by excluding a certain area 14b based on the current position of the loading machine 14 from the current course area 1, the position data for the course area 1 (course area 1 shape) are updated. That is, even if the loading machine 14 does not comprise a device for measuring the bucket position, updating the position data for the course area 1 can be performed accurately so long as a device is provided for measuring the current position of the loading machine 14.
A 27th invention is the 26th invention wherein the certain area excluded from the current course area is an area within reach of the loading mechanism of the loading machine.
Based on this 27th invention, as diagrammed in FIG. 40(a), an area 14b within a range reachable by the loading mechanism (arm) of the loading machine 14 from the current position of the loading machine 14 is determined, that area 14b is excluded from the course area 1, and thereby the position data for the course area 1 (course area 1 shape) are updated. In other words, even if the loading machine 14 is not equipped with a device for measuring the bucket position, updating the position data for the course area 1 can be performed accurately so long as a device is provided for measuring the current position of the loading machine 14.
A 28th invention is the 26th invention wherein the certain area excluded from the current course area is inside an area within reach of the loading mechanism of the loading machine, and an area of about size of main body of the loading machine.
Based on this 28th invention, as diagrammed in FIG. 40(a), an area 14a of about the size of the main body of the loading machine 14, inside the area 14b within the range reachable by the loading mechanism (arm) of the loading machine 14, is found from the current position of the loading machine 14, that area 14a is excluded from the current course area 1, and thereby the position data of the course area 1 (course area 1 shape) are updated. In other words, even if the loading machine 14 is not equipped with a device for measuring the bucket position, updating the position data for the course area 1 can be performed accurately so long as a device is provided for measuring the current position of the loading machine 14.
A 29th invention is the 26th invention, wherein the certain area excluded from the current course area is inside an area within reach of the loading mechanism of the loading machine, and an area that is located at a constant distance from the boundary of the course area.
Based on this 29th invention, as diagrammed in FIG. 41, an area 14c such that the distance from the boundary 1a of the course area 1 is constant, inside the area 14b within the range reachable by the loading mechanism (arm) of the loading machine 14, is found from the current position of the loading machine 14, that area 14c is excluded from the current course area 1, and thereby the position data of the course area 1 (course area 1 shape) are updated. In other words, even if the loading machine 14 is not equipped with a device for measuring the bucket position, updating the position data for the course area 1 can be performed accurately so long as a device is provided for measuring the current position of the loading machine 14.
A 30th invention is the 13th invention, wherein the vehicle is an unmanned vehicle that is loaded with a load by a loading machine; relative position indication means for indicating relative positions relative to the loading machine is provided; and position data for the course area are updated by excluding an area referenced to positions indicated by the relative position indication means from current course area.
Based on the 30th invention, relative positions (bucket positions) relative to the loading machine 14 are indicated by the relative position indication means, and areas based on those indicated positions are excluded from the current course area 1, whereby the position data of the course area 1 (course area 1 shape) are updated. In other words, in cases where the form of the excavation work lacks a certain regularity, a range that should be excluded from the course area 1 can be directly indicated by the operator, and the position data for the course area 1 accurately updated.
A 31st invention is the 13th invention, wherein the.vehicle is an unmanned vehicle that is loaded with a load by a loading machine, and position data for the course area are updated by adding, to current course area, an area within range occupied by the unmanned vehicle at a target point that should be reached by the unmanned vehicle.
Based on this 31st invention, as diagrammed in FIG. 39(a), from the target point which the unmanned vehicle 2 should reach is found an area 2a within the range a occupied by the unmanned vehicle 2 at the target point, and that occupation range area 2a is added to the current course area 1, thereby updating the course area 1 position data (course area 1 shape). In other words, even if the loading machine 14 is not equipped with a device for measuring the bucket position, updating the position data for the course area 1 can be performed accurately so long as a device is provided for measuring the current position of the loading machine 14 (that is, the target point of the unmanned vehicle 2).
A 32nd invention is the 13th invention wherein the vehicle is an unmanned vehicle that is loaded with a load by a loading machine, and position data for the course area are updated either by excluding a certain area referenced to current position of the loading machine from current course area, or by adding area within range occupied by the unmanned vehicle at target point that should be reached by the unmanned vehicle to current course area.
Based on this 32nd invention, as diagrammed in FIG. 40(a), the course area 1 position data (course area 1 shape) are updated by excluding a certain area 14b based on the current position of the loading machine 14 from the current course area 1, or, alternatively, as diagrammed in FIG. 39(a), the course area 1 position data (course area 1 shape) are updated by finding, from the target point that the unmanned vehicle 2 should reach, an area 2a within the range occupied by the unmanned vehicle 2 at the target point, and adding that area 2a within that occupied range to the course area 1. In other words, even if the loading machine 14 is not equipped with a device for measuring the bucket position, updating the position data for the course area 1 can be performed accurately so long as a device is provided for measuring the current position of the loading machine 14 (that is, the target point of the unmanned vehicle 2).
A 33rd invention is the 32nd invention, further comprising selection means for selecting whether the course area is to be expanded or contracted, according to type of work being done by the loading machine, wherein the course area position data are subjected to updating processing according to results of selection made by the selection means.
Based on the 33rd invention, selection means for selecting whether the course area 1 is to be expanded or contracted, according to the work form of the loading machine 14, are also comprised, and the course area 1 position data are subjected to updating processing according to the results of the selection made by those selection means.